How to Bypass the Sucuri Website Firewall

A web application firewall (WAF) is an effective tool for repelling external threats that could negatively impact a website. WAF works by filtering, monitoring, and blocking HTTP traffic to and from a web application. Such a firewall acts as a protective shield between your website and incoming threats.

Websites are equipped with firewalls by their owners to protect their data and website content against all kinds of threats - from cybersecurity breaches and DDoS issues to spam and simple misuse.

Whether you are running a simple blog, company website, an e-commerce store, or providing cloud-based services, firewalls are crucial for keeping user data safe and maintaining uptime.

However, legitimate users can sometimes get stuck in these protections. That is the topic we will explore today by taking a closer look at the Sucuri Firewall, why you might get blocked by it, and how you can deal with those frustrating errors appropriately.

What Is the Sucuri Website Firewall?

The Sucuri Website Firewall is a specialized WAF developed to protect websites from online threats. Acquired by GoDaddy in 2017, Sucuri has since expanded its services to a broad audience – from small business owners who were the primary focus of GoDaddy to major enterprise brands.

The Sucuri WAF works as a reverse proxy. It mediates between a website’s server and its visitors by inspecting incoming traffic and filtering out malicious requests before they even reach the server.

Some of the main threats it defends against include:

• DDoS attacks
• Malware injections
• Brute-force login attempts
• SQL injection and XSS vulnerabilities
• Traffic floods from suspicious bots

The Sucuri firewall is user-friendly and known for its efficiency, earning the trust of millions of sites worldwide to keep website content secure.

Why Sucuri Might Be Blocking You

If you are seeing a “403 Forbidden” error or an “Access Denied” message, it likely means the Sucuri firewall is doing its job - but perhaps a little too aggressively. Here’s why you might get flagged:

• VPN and proxy

If your connection goes through an intermediate server, such as a VPN or a proxy, your IP address may raise suspicions. The firewall automatically blocks traffic from known risky sources.

• Browser anomalies

Outdated or misconfigured browsers can sometimes trigger the firewall. Missing headers, odd user agents, or suspicious cookies can all raise red flags.

• IP flagging

If your IP was previously linked to spam, hacking attempts, or even a compromised botnet, it may get blacklisted by the Sucuri system.

The first clue that you are blacklisted is the type of error you see. Sucuri often attaches an error reference ID to its blocks. You can also check your IP against public blacklists. If you confirm you are blacklisted, contacting the site owner or Sucuri support may help you restore the access.

Common Techniques for Bypassing the Sucuri Firewall

The very nature of Sucuri WAF dictates the main directions in which you can circumvent it. The most effective techniques would be the following:

• Direct IP address

Since Sucuri WAF works as a reverse proxy, it hides the IP of the origin web server. If you manage to uncover the actual IP and send the request directly to it, you will avoid getting blocked.

However, similarly to bypassing other WAF protections, such as Cloudflare or PerimeterX , this method requires using various tools to identify the direct IP address. They can’t guarantee success in this endeavor every time, as the IP is heavily masked.

• Proxy

As mentioned before, using a proxy can flag your IP as suspicious. That doesn’t mean you can’t use a proxy to change this IP address , and hope the next one won’t be flagged the same way.

Even if it does, one of multiple IPs rotating will eventually do the trick. Trusted proxy providers typically have large pools of IPs to choose from and will allow you to rotate them to avoid any issues stemming from a single IP being blacklisted.

• User agent rotation

Rotating user agents allows switching between web identifiers to imitate unique user requests, erasing the association between these requests that would eventually lead to identifying a single end-user.

The user agent is an HTTP header that contains data regarding your browser name and version, device type, operating system, and other user-specific information. If you send multiple requests using the same user agent, or there is some kind of issue with the one you use, you will likely get blacklisted.

Deploying user agent rotators or learning how to change your user agent yourself will help you prevent Sucuri from blocking you.

Summing-up

The Sucuri firewall protects websites against online hazards, such as cyberattacks, malware, DDoS attacks, and data breaches. Understanding why your IP got flagged might give you a clue where the issue lies and what steps you need to take to solve it. Using a proxy, rotating user agents, and trying to dig your way to the direct IP address to send your request there will let you circumvent the Sucuri firewall and get away from being blacklisted.